/**
 * This jQuery plugin displays pagination links inside the selected elements.
 *
 * @author Gabriel Birke (birke *at* d-scribe *dot* de)
 * @version 1.2
 * @param {int} maxentries Number of entries to paginate
 * @param {Object} opts Several options (see README for documentation)
 * @return {Object} jQuery Object
 */
///获取cookie值   
function getCookie(NameOfCookie) {
    // 首先我们检查下cookie是否存在.   
    // 如果不存在则document.cookie的长度为0   
    if (document.cookie.length > 0) {
        // 接着我们检查下cookie的名字是否存在于document.cookie   
        // 因为不止一个cookie值存储,所以即使document.cookie的长度不为0也不能保证我们想要的名字的cookie存在   
        //所以我们需要这一步看看是否有我们想要的cookie   
        //如果begin的变量值得到的是-1那么说明不存在   
        var begin = document.cookie.indexOf(NameOfCookie +"=");
        if (begin != -1) {
            // 说明存在我们的cookie.  
            begin += NameOfCookie.length + 1; //cookie值的初始位置   
            var end = document.cookie.indexOf(";", begin); //结束位置   
            if (end == -1) end = document.cookie.length; //没有;则end为字符串结束位置   
            return unescape(document.cookie.substring(begin, end));
        }
    }
    return 10;
    // cookie不存在返回null   
}
var items_pagesize = getCookie("pagesize|http//" + location.host);

jQuery.fn.pagination = function (maxentries, opts) {
    opts = jQuery.extend({
        items_per_page: items_pagesize,
        num_display_entries: 8,
        current_page: 0,
        num_edge_entries: 2,
        link_to: "javascript:void(0);",
        prev_text: "上一页",
        next_text: "下一页",
        ellipse_text: "...",
        prev_show_always: true,
        next_show_always: true,
        callback: function () { return false; }
    }, opts || {});

    return this.each(function () {
        /**
        * Calculate the maximum number of pages
        */
        function numPages() {
            return Math.ceil(maxentries / opts.items_per_page);
        }

        /**
        * Calculate start and end point of pagination links depending on 
        * current_page and num_display_entries.
        * @return {Array}
        */
        function getInterval() {
            var ne_half = Math.ceil(opts.num_display_entries / 2);
            var np = numPages();
            var upper_limit = np - opts.num_display_entries;
            var start = current_page > ne_half ? Math.max(Math.min(current_page - ne_half, upper_limit), 0) : 0;
            var end = current_page > ne_half ? Math.min(current_page + ne_half, np) : Math.min(opts.num_display_entries, np);
            return [start, end];
        }

        /**
        * This is the event handling function for the pagination links. 
        * @param {int} page_id The new page number
        */
        function pageSelected(page_id, evt) {


           // $("#hiddpage").val($("#dropPageSize").val());
            current_page = page_id;
            drawLinks();
            var continuePropagation = opts.callback(page_id, panel);
            if (!continuePropagation) {
                if (evt.stopPropagation) {
                    evt.stopPropagation();
                }
                else {
                    evt.cancelBubble = true;
                }
            }
            return continuePropagation;
        }

        /**
        * This function inserts the pagination links into the container element
        */
        function drawLinks() {
            panel.empty();

            var interval = getInterval();
            var np = numPages();
            // This helper function returns a handler function that calls pageSelected with the right page_id
            var getClickHandler = function (page_id) {
                return function (evt) { return pageSelected(page_id, evt); }
            }
            // Helper function for generating a single link (or a span tag if it's the current page)
            var appendItem = function (page_id, appendopts) {
                page_id = page_id < 0 ? 0 : (page_id < np ? page_id : np - 1); // Normalize page id to sane value
                appendopts = jQuery.extend({ text: page_id + 1, classes: "" }, appendopts || {});
                if (page_id == current_page) {
                    var lnk = jQuery("<span class='current'>" + (appendopts.text) + "</span>");
                }
                else {
                    var lnk = jQuery("<a>" + (appendopts.text) + "</a>")
						.bind("click", getClickHandler(page_id))
						.attr('href', opts.link_to.replace(/__id__/, page_id));


                }
                if (appendopts.classes) { lnk.addClass(appendopts.classes); }
                penelItem.append(lnk);

            }
            

            var option = "";

            for (var i = 1; i <= ((opts.items_per_page / 10) < 5 ? 5 : (opts.items_per_page / 10)) ; i++) {
                if (i * 10 == opts.items_per_page) {
                    option += "<option value='" + (i * 10) + "' selected='selected'>  " + (i * 10) + " </option>";
                } else {
                    option += "<option value='" + (i * 10) + "' > " + (i * 10) + " </option>";
                }
            }
            var html = jQuery("<div style='padding-top: 3px; margin-top:-3px; float:right;'>每页行数：<select  style='width:50px;height:22px;' id='dropPageSize' onchange='$(\"#hiddpage\").val($(this).val())'  >" + option + "</select><div>").bind("change", getClickHandler(0));
            panel.append(html);

            

            var penelItem = jQuery("<div style='text-wrap:normal; float:right;'></div>");
            panel.append(penelItem);
            // Generate "Previous"-Link
            if (opts.prev_text && (current_page > 0 || opts.prev_show_always)) {
                appendItem(current_page - 1, { text: opts.prev_text, classes: "prev" });
            }
            // Generate starting points
            if (interval[0] > 0 && opts.num_edge_entries > 0) {
                var end = Math.min(opts.num_edge_entries, interval[0]);
                for (var i = 0; i < end; i++) {
                    appendItem(i);
                }
                if (opts.num_edge_entries < interval[0] && opts.ellipse_text) {
                    jQuery("<span>" + opts.ellipse_text + "</span>").appendTo(penelItem);
                }
            }
            // Generate interval links
            for (var i = interval[0]; i < interval[1]; i++) {
                appendItem(i);
            }
            // Generate ending points
            if (interval[1] < np && opts.num_edge_entries > 0) {
                if (np - opts.num_edge_entries > interval[1] && opts.ellipse_text) {
                    jQuery("<span>" + opts.ellipse_text + "</span>").appendTo(penelItem);
                }
                var begin = Math.max(np - opts.num_edge_entries, interval[1]);
                for (var i = begin; i < np; i++) {
                    appendItem(i);
                }

            }
            // Generate "Next"-Link
            if (opts.next_text && (current_page < np - 1 || opts.next_show_always)) {
                appendItem(current_page + 1, { text: opts.next_text, classes: "next" });
            }

            jQuery("<div><span>总记录数：<font color='#2088da'>" + (maxentries) + "</font>&nbsp;&nbsp;&nbsp;当前页：<font color='#2088da'>" + ((current_page) <= 0 ? 1 : (current_page + 1)) + "</font> /<font color='#2088da'> " + (np) + "</font> </span></div>").appendTo(panel);

        }

        // Extract current_page from options
        var current_page = opts.current_page;

        // Create a sane value for maxentries and items_per_page
        maxentries = (!maxentries || maxentries < 0) ? 1 : maxentries;
        opts.items_per_page = (!opts.items_per_page || opts.items_per_page < 0) ? 1 : opts.items_per_page;
        // Store DOM element for easy access from all inner functions
        var panel = jQuery(this);
        // Attach control functions to the DOM element 
        this.selectPage = function (page_id) { pageSelected(page_id); }
        this.prevPage = function () {
            if (current_page > 0) {
                pageSelected(current_page - 1);
                return true;
            }
            else {
                return false;
            }
        }
        this.nextPage = function () {
            if (current_page < numPages() - 1) {
                pageSelected(current_page + 1);
                return true;
            }
            else {
                return false;
            }
        }
        // When all initialisation is done, draw the links
        drawLinks();
        // call callback function
        //  opts.callback(current_page, this);
    });
}


